Method of making laminated metal



May 4, 1937.- s. L. INGERSOLL METHOD OF .MAKING' LAMINATED METAL 2 Sheets-Sheet 1 Filed Nov. 23, 1934 E 7UP (fie view oPJreyer-sa/Z.

y 4, 1937. s. L. INGERSOLL, 2,079,213

- I METHOD OF MAKING LAMINATED METAL Filed Nov 23, 1934 2 Sheets-Sheet 2 Iv l //f //W4 Patented May 4, 1937 UNITED STATES 2,079,213 DIETHOD OF MAKING LAMINATED METAL Stephen L. Ingersoll, Chicago, Ill., assignor, by

mesne assignments, to Borg-Warner Corporation, Chicago, 11]., a corporation of Illinois Application November 23, 1934, Serial No. 754,462

. 9. Claims. This invention relates to the preparation of laminated metal articles having a surface metal 1,868,749 entitled Laminated metal and process of making same", issued July 26, 1932, I have described and claimed the process of forming laminated metal sheets by preparing two metal slabs 20 such as stainless steel slabs with finished surfaces, placing said slabs in juxtaposed position with a separating composition therebetween, sealing the slabs together along their adjoining peripheral edges and casting another metal such 25 as mild steel entirely around said slabs to become integrally bonded thereto. I have now provided a process wherein a plurality of pairs of juxtaposed slabs can be used in one casting operation to form a large compositemetal ingot from 3 which a plurality of pairs of metal articles can be rolled.

In my co-pending application entitled Method and apparatus for casting composite metal ingots", Serial No. 753,079 filed November 15. 1934,

Lhave described and claimed a method for suspending the metal slabs in a mold by means of breather pipes welded to the tops of the slabs to permit escape of gases from the space between the slabs. According to my present proc- 40 ess, breather pipes can be used in an identical manner as disclosed in my co-pending application. It should be understood, however, that any other means of suspending the slabs in the mold may be used without departing from the prin- 45 ciples of this invention.

This process provides for the casting of large composite metal ingots having a plurality of pairs of metal slabs disposed at the core of the ingot. The'slabs are joined together either in 50 superimposed or laterally extended relation with separating bars positioned between each pair of slabs along the top or side edges thereof. The separating bars are welded to the top and bottom or sides of the slabs so as to form an integral 55 insert which may be suspended as a unitint a mold in spaced relation from the walls of the mold. Molten metal having different characteristics from the metal of the slab but having similar characteristics to the metal of the separating bars is then cast entirely around the slabs to form the ingot of this invention which is subjected to a slabbing down or rolling operation after cooling to form a pack having the pairs of partially rolled metal slabs in the center thereof. The separating bars being identical with the case metal fuse together with this metal to form an integral mass. The slabbed down pack is next cut into sections each of which have a pair of the partially rolled metal slabs in the center thereof. Each section is then rolled into a' sheet form, the marginal edges are clipped oii and the laminated metal sheets spring apart.

It is therefore an object of this invention to provide a process for casting large composite metal ingots having a plurality of pairs of metal slabs disposed in the core and integrally bonded with the surrounding metal. Another object of this invention is to provide a process for preparing a plurality of pairs of laminated metal sheets which process involves only a single casting operation.

A further object of this invention is to provide a. method for the mass production of laminated metal sheets wherein a plurality of pairs of said sheets can be formed by a single casting operation.

Other and further objects of this invention will be apparent from the following detailed description of the annexed sheets of drawings which illustrate preferred embodiments of the invention.

' On the drawings:

Figure 1 is a front elevational view with parts in cross section, illustrating the manner in which a plurality of pairs of super-imposed metal slabs are suspended in a mold in spaced relation from the Walls thereof.

Figure 2 is a cross sectional view taken substantially along the line 11-11 of Figure 1.

Figure 3 is a cross sectional view of an ingot formed by casting molten metal into the mold illustrated in Figures 1 and 2.

Figure 4 is a plan view of a partially rolled or slabbed down pack formed from the ingot shown in Figure 3.

Figure 5 is a view taken substantially along the line V-V of Figure 4. a I

Figure 6 is a brokencross sectional view of the pack formed afterthe rolling operation is completed.

Figure '1 is a broken end elevation at a composite metal sheet formed according to this invention.

Figure 8 is a top plan view illustrating an alternative method for suspending the slabs in a mold.

Figure 9 is a view taken substantially along the line IX-IX of Figure 8,

As shown on the drawings:

In Figures 1 and 2 the reference numeral l8 indicates generally a relatively deep mold composed of half sections II and I2. The side walls of the mold l0 are provided with laterally extending ears I3 and M. Bolts l5 and I6 are pivoted in the ears l3 and M respectively. A supporting bar l1 of sufficient length to extend across the width of the mold is provided with bifurcated ends through which the bolts l5 and I6 may extend. Wing nuts l8 and H are then threaded down on the bolts l5 and I6 to clamp the bar II on top of the mold.

The bar I1 is provided with apertures in the central portion thereof of sufficient size to allow the breather pipes 20 and 2| to extend therethrough. Nuts 22 and 23m threaded engagement with the breather pipes 20 and 2| maintain the bar l1 in proper spaced relation from the bottom of the breather pipes, while nuts 24 and 25 are threaded on the breather pipes over the bar H to clamp the bar between the nuts 22 and 24 and 23 and 25. i

Rectangular metal slabs 26 and 21 are provided with smoothed and cleaned surfaces by a pickling or other cleaning operation and are then placed in juxtaposed relation with a. separating material 28 therebetween. The adjoining peripheral edges of the slabs 26 and 21 are next welded together by a weld similar to the weld 29 shown on the lowermost pair of slabs in Figure 2. The weld does not extend across the space occupied by the breather pipes 20 and 2|. These breather pipes, on the other hand, are welded to the tops of the slabs 26 and 21 as shown at 30 and 3| to secure the breather pipes to the slabs in communication with the space between the slabs.

A spacer bar 32 is next welded to the bottom of the slabs 26 and 21 around their outside peripheral edges by a weld 33. The bar 32 is provided with holes 34 and 35 extending therethrough. The weld 28 around the adjoining peripheral edges of the slabs 26 and 21 does not extend across these openings 34 and 35.

A second pair of metal slabs 36 and 31 welded together in an identical manner with the slabs 26 and 21 and having a separating medium therebetween are welded around their outside peripheral top edges to the bottom of the bar 32 by a weld 38.

The bottom of the slabs 36 and 31 is welded to another spacer bar 38 having holes 39 and 46 therethrough by means of a weld 4|.

Another pair of metal slabs 42 and 43 secured together by the weld 29 with a separating composition therebetween are welded to the bottom of the bar 38 around their outside top peripheral edges by means of a weld 44.

As pointed out above, the weld 23 joining the pairs of metal slabs together in juxtaposed relation does not extend over the openings in the spacer bars 32 and 38 so that the breather pipes 28 and 2| are in communication withthe spaces between each pair of slabs.

The so-welded together pairs of super-imposed slabs are suspended from the breather pipes 20 aomara and 2| and are held in spaced relation from the walls of the mold III by the supporting bar l1.

Molten metal having different characteristics than the metal of the slabs is next poured entirely around the slabs to form the ingot as shown in Figure 3. The spacer bars 32 and 38 and the breather pipes 26 and 2| are preferably formed of metal having the same characteristics as the cast metal so that they will partially melt during the casting operation and fuse with the cast metal to form a homogeneous mass. The cast metal also fuses with the slab metal to become bonded therewith. The ingot 45 shown in Figure 3 therefore is composed of cast metal having a core composed of the plurality of pairs of metal slabs in spaced super-imposed relation. The separating compound between the slabs prevents the same from fusing together during the casting operation.

tegral part of the cast metal are compressed 5 more than the slabs since they are somewhat softer. This feature is very advantageous since it provides depressed portions 41 and 48 (Figure 5) between the slabs. The slabbed down pack 46 is next out along the lines XX (Figure 5) to provide three separate packs each of which provide two composite metal sheets as will be hereinafter described. The pack 46 is cut in the center of the depressed portions 41 and 48 and the lines X-X are thereby readily positioned.

Each of the portions 49, 56 and 5| of the pack 46 are next rolled down into the sheet or plate pack 52 shown in Figure 6. The marginal edges of the rolled down pack 52 are next clipped off along the lines Z-Z to provide two laminated metal sheets such as the sheet 53 shown in Figure 7. Each sheet 53 is composed of a surface layer 54 of the slab metal integrally bonded with a backing layer 55 of the cast metal.

In Figures 8 and 9 I have shown a modified arrangement of the slabs in a mold which is less deep than the mold shown in Figures 1 and 2.

As shown in Figures 8 and 9, an elongated rectangular mold 60 is provided with laterally extending ears 6| and 62 on the sides thereof. The

ears 6| and 62 are adapted to receive pivotally mounted bolts 63 and 64 having wing nuts 65 and 66 threaded thereon.

A supporting bar 61, of sufficient length to extend across the length of the mold is provided with bifurcated ends 68 and 63 adapted to receive respectively the bolts 63 and 64 therethrough. The wing nuts 65 and 66 clamp the bar 61 on top of the mold 68.

Since the bar 61 is necessarily of considerable length,'a second supporting bar 16 is provided to reinforce the bar 61 and prevent the same from sagging. The bar 16 extends across the width of the mold resting on the top of the mold walls and is provided with a depressed central portion 1| for receiving the bar 61. The bars 61 and 10 are then clamped together by means of a bolt 12 and a nut 13.

The bar 61 is provided, intermediate the ends thereof, with a plurality of holes adapted to rethe slabs become more integrally the slabs.

ceive breather pipes 14 to. "inclusive therethrough. The bar 61 is clamped to each breather pipe and maintained in spaced relation from the bottom of said pipe by means of nuts 88 and 8| threaded on the breather pipe above and below the bar in a manner identical with that described in connection with Figures 1 and 2.

Pairs of metal slabs 82 and 83; 84 and 85; 86 and 8'! areeach welded together in juxtaposed relation along their adjoining peripheral edges with a weld '88 to provide a plurality of pairs of metal inserts. are welded to the tops of the slabs 82 and 83 by welds 88 and 80. The breather pipes I6 and H are welded to the tops of the slabs 84 and 85 by welds 8| and 82 while the breatherpipes "I8 and I9 are welded to the flat tops of the slabs 86 and 81 by welds 83 and 84. The welds 88 joining the slabs together in juxtaposed relation do not extend across the space occupied by the breather pipes so that each pipe is in communication with the space between the slabs. A separating medium is inserted in this space or is coated onto the adjoining surfaces in each pair of slabs.

The respective pairs of slabs are placed in lateral alignment and spacer bars 85 and 86 are inserted between adjoining sides of the slabs. The spacer bar 95 is welded to the slabs 82 and 83 around the outer edges of said slabs by a weld 81. This bar is also welded to the sides of the slabs 84 and 85 which adjoin the slabs 82 and 83 by means of a weld 98.

The opposite sides of the slabs 84 and 85 are welded to the spacer bar 86 by means of a weld 88 while the slabs 86 and 81 are also welded to in spaced relation from the walls of the mold and molten metal of different characteristics from the metal of the metal slabs is cast entirely around The breather pipes and spacer bars are preferably formed of metal having the same characteristics as the cast metal so that they will partially melt down and become integrally fused with the cast metal to form a homogeneous mass. The cast metal also fuses into the exposed surfaces of the metal slabs to become bonded thereto. After the cast metal has solidified, the resulting ingot is stripped from the mold and rolled in an identical'manner described in connection with Figures 3 to 7 inclusive. It should be understood that the welds 81 to I08 need not be continuous welds since the spacer bars may be satisfactorily secured to the slabs by a plurality of spaced spot or tack welds. The spacer bars 85 and 86 need not have holes permitting communication of the spaces between the adjoining slabs since each of the slabs are provided l with breather pipes for this purpose. The spacer bars 85 and 86, however, could be provided with holes similar to the holes in the spacer bars 32 and 38 and a breather pipe would then only be The breather pipes 1,4 and I5v providing means for suspending the slabs in spaced relation from the walls of the mold and at the same time permitting the escape ofgases from the spaces between the slabs during the casting operation. Compressed air or other fluids can be blown through one of the breather pipes and allowed to escape out of the other breather pipe in each pair of the slabs for controlling the cooling rate during the casting operation.

From the above description it is obvious that I have now provided a process wherein a plurality of pairs of metal slabs may be used in asingle casting operation for providing a plurality of pairs of metal articles. While three pairs of metal slabs have been illustrated in each instance on the drawings/it should be understood that the invention can be applied to the casting of the molten metal around two or more pairs of slabs. This process greatly reduces manufac turing costs of laminated metal articles since it provides for the mass production of such articles wherein large ingots are prepared by a single casting operation. These ingots having a plurality of pairs of spaced slabs in the core thereof make possible the rolling down of the ingot to form a slabbed down pack with allof the slab metal sealed from the atmosphere. The pack is then clipped between the pairs of slabs without exposing the slab metal to the atmosphere. Each clipped portion can then be further rolled to the If a single pair of large slabs were inserted in a mold to form the core of a large ingot, this ingot could not be rolled on standard size rolling mills direct to sheet or plate form without shearing into the slab metal to separate portions therefrom of a rollable size. This would expose the slab metal tothe atmosphere and might destroy the original prepared surfaces of the slabs. It was therefore necessary heretofore to provide small ingots so that they could be rolled direct to the finished plate, strip or sheet without exposing the slabs to the atmosphere.

The process is applicable to the casting of a ferrous metal about non-ferrous metal slabs as well as to the casting of a ferrous metal such as mild steel around stainless steel slabs.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I,- therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. The method of forming a composite metal ingot, comprising the steps of inserting a separating material between opposed broad faces of paired metal slabs of a plurality of paired metal slabs, sealing certain edges of said pairs by welding corresponding edges of the slabs therein together and leaving other edges unsealed, arranging said pairs of slabs in a common plane with their unsealed edges in opposed relation, coupling said pairs together by means of sealing members disposed between the opposed edges, and casting molten metal of different characteristics than the slab metal entirely about said slabs.

2. The process of forming a composite metal ingot comprising welding together a pair of metal slabs in juxtaposed face. to face relation with a separating medium therebetween, capping an edge of said slabs with a separator bar and welding said bar to said slabs, preparing another pair of slabs welded together in such juxtaposed relation with a separating medium therebetween, welding an edge of said other pair of slabs to said separator bar, supporting said pairs of slabs in an ingot mold, and casting molten metal of different characteristics than the slab metal entirely about said slabs.

3. The method of forming a composite metal ingot, comprising the steps of preparing a plurality of paired metal slabs, the slabs ineach pair being slightly spaced and in parallelism and there being a weld preventing material within the space between the paired slabs, placing said pairs of slabs in edge to edge relation with an apertured separator bar between such edges and with the apertures in said bar disposed for providing communication with the spaces between the paired slabs, welding said separator bar to the paired slabs on each side thereof, welding a breather pipe to the edge of one of said pairs of slabs and in communication with the space between such pair, suspending all of said slabs from said breather pipe, and casting molten metal of different characteristics than the slab metal entirely about said slabs.

4. The process of forming composite metal ingots, comprising the steps of arranging a plurality of metal slabs in pairs with the slabs of each pair in parallel juxtaposed position, securing the slabs in each pair together about their peripheral edges to provide an envelope between the slabs therein, there being provided a separating composition in each of such envelopes, placing the so formed pairs of slabs in edge to edge relation with a metallic separator bar between such edges, said bars having openings therein in communication with the envelopes of thepairs on each side thereof, welding the separator bars to such edges of the pairs, suspending the thus assembled slabs and pairs in spaced relation from the walls of a mold, and casting a metal having the same characteristics as the separator bars but of different characteristics than the slab metal entirely about said slabs.

5. The process of forming composite metal ingots, comprising the steps of arranging a plurality of metal slabs in pairs with the slabs of each pair in parallel juxtaposed position, securing the slabs in each pair together about their peripheral edges to provide an envelope between the slabs therein, there being provided a separating composition in each of such envelopes, placing the so formed pairs of slabs in edge to edge relation with a metallic separator bar between such edges, said bars having openings therein in communication with the envelopes of the pairs on each side thereof, welding the separator bars to such edgesof the pairs, suspending the thus assembled slabs and pairs in spaced relation from the walls of a mold, casting a metal of different characteristics than the slab metal about the insert, allowing the cast metal to cool thereby forming an ingot, rolling the ingot upon a plane parallel to the plane of said slabs thereby forming a flat pack, cutting said pack into lengths containing the metal of one pair of said slabs in each length, further rolling each of said lengths into flat laminated bodies, clipping the marginal edges from said bodies and separating the laminations thereof.

6. The process of forming a plurality of pairs of metal sheets, the process comprising the steps of forming an integral metal insert from a plurality of metal slabs, weld preventing material and metal coupling bars, by arranging said slabs in pairs with the slabs in each pair secured side by side with broad side surfaces in opposed relation' and with a quantity of said weld preventing material upon such surfaces,- placing said pairs concatenatively in edge to edge relation within a common plane and with said metal coupling bars between said edges of adjacent pairs, securing said bars to such edges, supporting said insert in a mold in spaced relation with the walls thereof, casting a metal of different characteristics than the slab metal entirely around said insert to form an ingot, removing such ingot from the mold, applying pressure to the ingot upon O posite surfaces in parallelism with the plane of said slabs thereby forming a flat pack, separating said pack into a plurality of smaller packs, each of which contains one of said pairs of slabs therein, further compressing each of said smaller packs upon'opposite faces parallel to the plane of the slabs therein, clipping the marginal edges from such further compressed packs, and separating such further compressed packs at the plane between the respective slabs therein.

7. The process of forming composite metal sheets, comprising the preparation of a composite metal ingot having a plurality of pairs of juxtaposed metal slabs in the core of the ingot, the pairs being in spaced edge to edge relation and the slabs in each of said pairs having opposed broad sides in spaced relation thereby effecting an interstitial plane therebetween, there being a weld preventing material in such interstices and the interstice within the respective pairs being substantially in a single plane, compressing said ingot upon a plane parallel to the interstitial plane of said pairs whereby to form a flat pack, dividing said pack at the sections between the pairs of metal slabs therein thereby forming a plurality of smaller packs, compressing each of the smaller packs upon its broad surfaces to form laminated sheets of the slabs therein, clipping the marginal edges from the so formed smaller packs and separating the same upon the plane between such sheets.

8. The herein described process of making laminated metal sheets, comprising the steps of forming a plurality of paired metal slabs, the slabs in each pair being disposed with a broad flat side of each in opposed slightly spaced relation with a quantity of weld preventing material therebetween and being joined about their peripheral edges in a manner sealing such space, aligning said pairs within a common plane with an edge of each pair in close proximity with an edge of another pair, joining said pairs together by welding metal bars thereto between such proximate edges, and casting a metal of different characteristics than the slab metal entirely about said slabs.

9. The method of forming a composite metal ingot, comprising the herein described steps of securing flatly together in pairs a plurality of metal slabs with an interstice between the slabs in the respective pairs and with a weld preventing material within such interstices, arranging said pairs coplanary in edge to edge relation with a separator bar between such edges, and joining said edges in such a manner as to obstruct those parts of the interstices coinciding therewith, and casting molten metal of different characteristics than the slab metal entirely about said slabs.

STEPHEN L. INGERSOLL. 

